Radio tuning dial



July 10, 1928.

L. E. DORSEY RADIO TUNING DIAL Filed June 12, 1926 2 sheets-sheet 1 Zeawd l zflonsegy ATTC- NEY WITNESS:

July 10, 1928. 1,677,075

L. E. DORVSEY I RADIO TUNING DIAL Filed June 12, 1926 2 Sheets-Sheet 2 LavnardED rS f] INVENTOR WITNESS: ATTORNEY Patented .[ul 10, 1928.

UNITED STA ES PATENT OFFICE.

LEONARD E DORSEY, OF COATESVILLE, PENNSYLVANIA.

RADIO TUNING DIAL.

Application filed June 12,

geared in a predetermined relation, so that b direct tuning may be effected by the use of a dial graduated to 360 degrees, a second dial permitting tuning when the pointer is moved through one revolution, of one-tenth of one degree, and a third dial permitting of tuning, to one one-hundredth of a degreel With the foregoing object in view, the invention consists in the novel construction and arrangement of elements described, illustrated and claimed, it being understood that modifications may be made Within the scope of the claim, without departing from the spirit of the invention.

In'the drawings forming part of this application,

Figure 1 is a view in elevation showing a radio panel and showing the three dialsem ployed in connection with the present construction.

Figure 2 is a diagrammatic view of the gearing.

Figure 3 is a section, on line33 of Figure 1.

Figure 4 is a perspective view of one of the knobs and pointers.

A radio panel 10 mounts a main axial element or shaft 11 for the tuning apparatus, this shaft being adapted for direct control by a knob 12 carrying'an ofi'set pointer 13 cooperating with dial 14 graduated to represent the 360 degrees of acircle.

Axle or shaft 11 mounts rigidly thereon a wheel 15 meshing with a pinion 16 on shaft 17, and this shaft carries a gear wheel 18. Wheel 18 meshes with pinion 19 on shaft 20 carrying knob 21 and pointer 22 cooperating with dial 23.

The gearing here referred to is proportioned to move the pointer 13 over one tenth of one division on the dial 14, or one-tenth of one degree, with a correspondingrotation of shaft 11 of the tuning element, this movement resulting from one revolution of knob 21.

1926. Serial No. 115,593.

When finer tuning is desired, the move ment of shaft 11 is regulated to one onehundredth of one degree by the use of the lower knob and the gearing controlled there- Knob 21 carries a second pinion 24 meshing with pinion 25 on shaft 26 mounting gear wheel 27, and the latter meshes with pinion 28 on shaft 29 controlled by knob 30 carrying pointer 31 cooperating with dial 32.

The elements of the train of gearing between shafts 29 and 11 are proportioned to effect the reduction specified, one complete revolution of knob 30 moving pointer 13 one one-tenth of a degree, or one thirty-sixhundredth of one revolution. This tenth is divided into tenths by the markings on the dial face, thus one hundredth of one degree tuning is effected.

It will be observed that the pointers are each provided with an offset end portion overlapping the graduated portion of the dial, the middle portion or the dial plates being depressed.

Having thus described the invention, what is claimed is:

In a radio tuning device, a main shaft, a

tuning element controlled thereby, a second shaft, earing for rotating the main shaft througli a predetermined angle, upon revolution ofthe second shaft, a third shaft, gearing for rotating the second shaft by the third shaft, and thence im arting movement to the main shaft tlrroug a fractional part of the angle first named, an intermediate shaft for each set of gearing, the shafts exclusive of the intermediate shafts including operating means, having their axes of rotation in parallel relation, and indicating devices on the third and second shafts, rotatable in a single direction and determining the extent of'rotation in the same direction of the main shaft and tuning element, in fractions of a degree and .in multiples of said fractional portions.

In testimony whereof I aflix my signature.

LEoiIARD E; DORSEY. 

